Terrestrial excavation



Nov. 5, 1935., J. s. MILLER TERRESTRIAL EXCAVATION Filed June l7, 1954 I-llI INVENTOR 5., /hm

- BY 6%@ Mam :nu Lv. "u" 5 willi!!hwllleflllllllllvwdru1nIlnl1fn.JNJl/ww.

ATTORNEYS.

Patented Nov. 5, 1935 UNITED sTATEs TERRE STRIAL EXCAVATION .lames S. Miller, Pittsburgh, Pa., assignor to The Dravo Contracting Company, a corporation of Pennsylvania Application June 7, 1934, Serial No. 729,434

1 Claim.

This invention relates to terrestrial excavation and consists in an instrument and in its mode of use. In the use of the instrument excavation is made, and, in desired cases, foundations established.

'Ihe instrument is illustrated in the accompanying drawing. Fig. I is a View in longitudinal section on the broken plane indicated at I-I, Fig. III; Figs. II and III are views in transverse section, on the planes indicated at II--II and III-III, Fig. I.

The instrument is of columnar form andlis essentially double-walled and tubular, and in convenient embodiment includes outer and inner walls I and 2 formed of steel pipe. By way of example, the outer wall may be of IO-inch, and the inner of 6-inch, pipe. The over-all length is, in this case,about 30 feet. For convenience in building, the outer wall, as shown, is formed in two parts united by a screw-threaded coupling 3. The assembled pipes surround and form an openended bore.

The outer pipe exceeds the inner in length. At the lower end a sharp edge is formed by a plate i of the shape of a conical frustum, uniting the edges of the two pipes. At the upper end a bar 5,

penetrating the outer pipe at a level above the upper end of the inner, aifords purchase for a hook or other device for engaging and moving the instrument about and, when desired, for withdrawing the instrument from an excavation.

Between the walls in the upper portion of the instrument is formed a manifold chamber 6, and from the manifold chamber a tube or tubes 'I (preferably a plurality: in this instance, six linch pipes) extend downwardly, and, penetrating the plate 4, terminate in nozzles 10. The nozzles advantageously terminate in a plane somewhat higher than that of the cutting edge of the instrument. The manifold chamber is closed above by a plug 8, which may conveniently be formed of Babbitt metal, and the downward communication from chamber 6 is limited to tubes 'I in suitable manner. As here shown, all the space between walls I and 2 and external of tubes I is iilled with concrete iilling 9; but, manifestly, by way of alternative, a plug of Babbitt metal or other convenient material might close the chamber below, as well as above, leaving open passageway to the tubes 'I only. A screw-threaded sleeve Ill, set in the outer pipe I, and adapted t afford separable connection for an hydraulic conduit (ordinarily a hose connected to a source of water supply) gives access to manifold chamber 6. In this sleeve a screen I I may be set, to keep large particles of rock or of other solid material from gaining entrance to the instrument. A pipe I2 (in this instance a 11/4 inch steel pipe) for the conveyance of compressed air enters at the upper end of the instrument, extends between the double walls, and opens through the inner wall 2 at a point near its lower end. But one pipe I2 is present in the instrument here illustrated; a plurality of such pipes may be provided, if desired. -At its upper end the pipe I2 is 10 adapted, as by the screw-threaded elbow I3, to be brought into separable connection with a source of pneumatic power--ordinarily a compressedair supply.

In operation, the instrument is set in vertical position upon the ground at the point where excavation is to be made, and water and air connections are made at II] and I3; then, the water being turned on, the combined effect of the jets spurted through nozzles lil and of gravity (augmented by pressure, if need be, or by the blows of a mallet delivered upon the upper end of the instrument) will cause the instrument to sink into the ground, with accumulation of mud in the lower end of the central bore. The flow of water may be continuous or intermittent, depending on the condition and quality of the ground in which excavation is being made. Compressed air is introduced through pipe I2, continuously or intermittently, and concurrently or in alternation with the iiow of water-all depending on the condition and quality of the ground-with the eifect that the earthy material accumulated in the central bore is blown out through the bore and discharged through the upper open end.

When penetration to the desired depth has been eifected, the instrument may be left in place; it may be left empty or filled with concrete; it may be withdrawn; and if withdrawn it may be replaced with concrete,-all as may be preferred or 40 required. Single, isolated excavations may be made, or a plurality, in groups or lines. Aligned excavations may be sunk along the perimeter of any desired area.

The instrument may be made of such proportions and of such materials as may be convenient. For example, if the size be large, the walls may be made of concrete, with suitable reenforcement; but in such case the sharp lower edge will advantageously be shod with steel.

Ordinarily the instrument will be cylindrical, but manifestly it may be of other cross-sectional shape; and, if it be rectangular, and if a plurality of instruments be sunk side by side, a continuous excavation of indefinite longitudinal extent may be effected.

One instance of practical application is that of sinking a hole in hard ground for the installation of a Well point. The instrument is sunk in the manner described to the required depth. 'I'he well point may then be inserted through the bore of the instrument, and remaining spaces may be filled with earth or other material. If desired, after the well point has been brought to place, the excavating instrument may be withdrawn.

Subterranean concrete columns may be formed by sinking the instrument and then filling the instrument in situ with concrete or, alternatively, the instrument may be withdrawn, and as it is Withdrawn the excavation may be lled with concrete.

I claim as my invention:

An excavating instrument of columnar form including two concentrically arranged walls surrounding and forming an open-ended bore,'the said Walls at their lower ends converging to a, cutting edge, the space between the Walls at the upper end of the instrument being closed above and below to form a manifold chamber, a. pluralit; of pipes leading from such manifold chamber downward between said Walls and terminating in nozzles adjacent such cutting edge, an airpipe extending between the walls from the upper end and opening laterally to the bore near the lower end of the instrument, and means for establishing communication from a source of Water supply to said manifold and from a source of compressed-air supply to the said air-pipe.

JAMES S. MILLER. 

